Archive of the former Yahoo!Groups mailing list: Yamaha CS80

Hello everyone!

Good to see a bit of traffic here lately after a long lull.  I know why I've been so distracted and I assume most folks have lots of stuff going on in their lives.  

I'm finally getting back to a long-term CS80 renovation / mod project after moving and job changes and other fun stuff.  I have a question for any of the techie types here.   For review, all the digital logic in the beasts use standard (and mostly still available) CMOS chips.  These are old DIP packages that only fit a hand full of gates in each chip.  They are all run off of +8.5v and -6.5v.  This weird arrangement fits in the 15-volt supply that the chips can handle and being offset allows analog switch chips (e.g. 4051, 4016) to process the analog control voltages and audio signals that are bi-polar around zero volts.

So, I want to add a bunch of new logic including an FPGA (tons of re-programmable gates) and a processor (maybe Arduino).

Mojo V3 - FPGA Development Board

			Mojo V3 - FPGA Development Board The Mojo is an FPGA development board with an Arduino compatible microcontroller on board. It is designed to be easy to use and a great introduction...
View on embeddedmicro.com	Preview by Yahoo

Again, the catch is that this board has 3.3volt digital I/O - which is actually pretty high compared to the latest chips!   So, I need to translate a lot of signals.  The old standbys were the 1488 and 1489 chips that were design to translate from 5volt TTL to +/- 12v (or lower) for RS-232 serial ports.  I might be able to use these but they would take up a ton of room and I'm not sure if they'll work with 3.3volt instead of 5volt.  I looked around a bit yesterday but found tons and tons of possible chips and was hoping someone here might know a good chip to use.  I'd like something that's 3.3volt on one side and up to the +8.5v/-6.5v Yamaha levels on the other side.  DIP or SOIC package would be fine and I'd like 8 or more channels in each chip with versions for one-way and bi-directional.

Any ideas on this idea in general?  On the Mojo board?  On the level-shifters?

Thanks and hope everyone is having a happy, music-filled summer!

 David